Green Mountain made its name with its Keurig coffee machines that popularized the small packets of coffee called pods to create convenient one-cup hot drinks. Green Mountain has sold 30 million single-cup machines, which are used in homes and offices around the world.

"What is Pepsi going to do? Unless they believe that Coke is dead wrong, they have no choice: Hello, SodaStream!" Citron wrote.

Green Mountain, based in Waterbury, Vt., told Reuters that its income leaped 28 percent to $138.2 million, or 91 cents per share, for the fiscal first quarter, which concluded Dec. 28. The company said that its net sales rose almost percent to $1.39 billion.

Green Mountain is also moving ahead with plans to introduce a new hot drink brewing system this fall.